(CNN) -- Lock up your children! Not forever, but tonight, certainly, and through the weekend -- until the fever passes. We both know they're wanting a piece of "Kick-Ass," Matthew Vaughn's hyper-violent, R-rated film of Mark Millar's hot-off-the-presses comic book, and that would just be oh-so-wrong.

A 20-year-old Brit who played the young John Lennon in "Nowhere Man," Aaron Johnson, plays gawky high school nerd Dave Lizewski. Dave is a comic book fan who decides he'd rather be a comic book hero. He seems to think this is a new notion, so he can't be that much of a culture vulture -- "Watchmen" and the underrated Ben Stiller movie "Mystery Men" both had similar starting points. Then again, they weren't real life.

Dave modifies a mail-order scuba suit -- dark green with yellow trim -- stands up to his neighborhood bully, and is soon enjoying a worm's eye-view of the pavement as the thug stomps him to within an inch of his life.

Most of us would probably reassess the wisdom of the plan at this point, but Dave emerges from the emergency room armed with a new-found tolerance for pain -- his nerves have been desensitized -- and with an unexpected cachet among the girls. So what if they assume he's gay?

So he tries again, and this time he holds his own against a couple of muggers -- and the whole fight winds up on YouTube. Kick-Ass is born.

If "Kick-Ass" had restricted itself to Kick-Ass -- a kind of Peter Parker without the spider scenario -- that would have been one thing; a teen not-so-super hero is a potent commercial idea; quirky, you might even say cute. But Millar goes further. Much further.

Our first glimpse of little Mindy Macready (Chloe Grace Moretz from "[500] Days of Summer") she's taking a bullet to the chest courtesy of Big Daddy (Nicolas Cage), a doting but decidedly paranoid father whose home schooling regimen consists of martial arts and weapons training.

When Dave gets seriously out of his depth confronting a bunch of drug-dealing pimps, 11-year-old Mindy reappears in Hit Girl guise: purple wig, black gloves, Zorro mask and tartan skirt. She makes short work of several heavies in vividly violent fashion (she's a dab hand with a blade), but it's her potty-mouth that is most likely to send sensitive souls into a lather.

"Kick-Ass" is offensive, sure. Bear that in mind when you choose your multiplex poison. But it's also recklessly, irredeemably entertaining, a glossy, bad- taste blockbuster mixing teddy bears and bazookas, microwaved wiseguys and post-modern takedowns. It's been a long time since a comic book movie allowed itself to be so facetious. As Dave observes, "With no power comes no responsibility." (It's a line only a Scot could have written.)

Back in his best beserker mode, Cage cheekily mimics TV Batman Adam West's emphatic diction but also leaves us in no doubt that this caped kook adores his daughter. It's a crackpot cameo that would unsettle most movies, but fits in snugly here, among such oddball characters as Christopher Mintz-Plasse's conflicted, weasily Red Mist, or Mark Strong's understandably infuriated mob boss.

Vaughn ("Stardust" and "Layer Cake") handles the action like a man who has studied his John Woo, his Brian De Palma and Quentin Tarantino and come to the conclusion that shoot-em-ups are kids' stuff. How right he was.